基于反应特性的可变截面甲醇水蒸气重整反应器优化

Optimization of Methanol Steam Reforming Reactor with Variable Cross-Sectional Based on Reaction Characteristics

研究了双套管式甲醇水蒸气重整(Methanol steam reforming,MSR)反应器在热空气加热条件下重整通道中的流场特征和催化床的温度分布特性,结果表明:催化床的温度沿流向迅速降低,最低温度在距催化床入口15 mm至20 mm处;然后,温度随流动方向逐渐升高至反应温度;此外,沿半径方向从中心到壁面催化床温度逐渐升高,热阻的存在使得催化床中心的温度低于周围的温度。根据这一反应特点,本文提出了一种变截面重整反应器,以充分利用供热能量,提高反应效率;然后利用响应面分析法(Response surface methodology,RSM)对变截面反应器的结构参数进行了优化。结果表明,在相同的边界条件下,加热通道重整入口处的外半径R_(1)=49.94 mm,最小横截面处的半径R_(2)=39.99 mm,最小横截面到催化床入口的距离D=98.44 mm,甲醇转化率显著提高。

The flow field characteristics in the reforming channel and the temperature distribution characteristics of the catalytic bed under the hot air heating condition are first investigated in a double-jacketed methanol steam reforming(MSR)reactor.It is shown that the temperature of the catalytic bed decreases rapidly along the flow direction,with the minimum temperature region at 15 mm to 20 mm from the catalytic bed inlet.And the temperature increases gradually with the flow direction to approach the heating temperature.In addition,the temperature gradually increases along the radius from the center to the wall,and heat transfer resistance makes the temperature in the middle of the catalyst bed lower than the temperature around.Based on this reaction characteristic,a variable cross-sectional reforming reactor is proposed in this paper to completely utilize the heat supply energy and improve the reaction efficiency.The response surface methodology(RSM)is then used to optimize the structural parameters of the variable cross-section reactor.It is shown that the methanol conversion is significantly increased at the same boundary conditions for the outer radius R_(1)=49.94 mm at the reforming inlet of the heating channel,the radius R_(2)=39.99 mm at the minimum cross-section and the distance D=98.44 mm from the minimum cross-section to the catalytic bed inlet.